xfce4-notes-plugin: update to 1.9.0

Change log:

1.9.0
======
- Remove unused variable
- Update deprecated autotools macros
- Do not mark text with ':' after '://' as a link (bug #52)
- Add support for links with scheme other than HTTP (bug #52)
- Fix missing-prototypes
- Create README.md. Update configure.ac.in
- Add basic gitlab CI
- Fix "Disabled labels on context menu are dark yellow"
- Fix a few deprecation warnings
- Fix make distcheck
- Fix blinking image on panel
- Remove commented code
- Update build system
- Fix make distcheck
- Remove deprecated gtk stock usage
- Fix build system
- Continue the gtk3 port
- Update URLs from goodies.x.o to docs.x.o (Bug #16171)
- po: update POTFILES.in
- gtk3: update css style with required changes from 3.20
- gtk3: drop libunique leftover flags and code
- gtk3: Drop support for GTK+-2.0
- bump post release
- Translation Updates:
  , Albanian, Amharic, Arabic, Armenian (Armenia), Asturian, Basque,
  Belarusian, Bulgarian, Catalan, Chinese (China), Chinese (Taiwan),
  Croatian, Czech, Danish, Dutch, Eastern Armenian, English
  (Australia), English (United Kingdom), Estonian, Finnish, French,
  Galician, German, Greek, Hebrew, Hungarian, Icelandic, Indonesian,
  Interlingue, Italian, Japanese, Kazakh, Korean, Latvian, Lithuanian,
  Malay, Norwegian Bokm奪l, Occitan (post 1500), Polish, Portuguese,
  Portuguese (Brazil), Romanian, Russian, Serbian, Slovak, Slovenian,
  Spanish, Swedish, Thai, Turkish, Ukrainian, Urdu, Urdu (Pakistan),
  Uyghur, Vietnamese

(gutteridge)